Bandwidth Control Apparatus, Bandwidth Control Method, Bandwidth Control System, and Bandwidth Allocating Apparatus

1. A bandwidth control apparatus that is connected with a plurality of other bandwidth control apparatuses in cascade through an upstream multiplexed signal line and a downstream multiplexed signal line, accommodates a plurality of access lines to which user terminals are connected and controls transmission bandwidths of the access lines, the bandwidth control apparatus comprising: a concentration unit that multiplexes upstream signals input from the plurality of access lines accommodated in the bandwidth control apparatus and upstream signals input from the other bandwidth control apparatuses located in a downstream direction and outputs the multiplexed signal as an upstream multiplexed signal, and branches a downstream multiplexed signal for broadcasting to the plurality of access lines accommodated in the bandwidth control apparatus as downstream signals and providing to the other bandwidth control apparatuses located in the downstream direction as the downstream signals; a first bandwidth state acquiring unit that collects bandwidth states of the plurality of access lines accommodated in the bandwidth control apparatus and acquires a bandwidth state in the bandwidth control apparatus; a second bandwidth state acquiring unit that acquires bandwidth states in the other bandwidth control apparatuses that are connected to one another in cascade; a bandwidth state allocating unit that calculates, a total bandwidth state of the bandwidth state acquired by the first bandwidth state acquiring unit and the bandwidth states acquired by the second bandwidth state acquiring unit, and allocates a transmission bandwidth to be controlled in the bandwidth control apparatus based on a ratio of the bandwidth state acquired by the first bandwidth state acquiring unit and the total bandwidth state; and a bandwidth state control unit that controls transmission bandwidths of the plurality of access lines accommodated in the bandwidth control apparatus on the basis of the transmission bandwidth allocated by the bandwidth state allocating unit.

2. The bandwidth control apparatus according to claim 1 , wherein the second bandwidth state acquiring unit acquires each of bandwidth states of the other bandwidth control apparatuses together with identification information for identifying the respective bandwidth control apparatuses, the bandwidth state allocating unit allocates a transmission bandwidth to be controlled in the bandwidth control apparatus based on a ratio of the bandwidth state acquired by the first bandwidth state acquiring unit and the total bandwidth state, and each of transmission bandwidths to be controlled in the other bandwidth control apparatuses, based on a ratio of each of the bandwidth states of the other bandwidth control apparatuses acquired by the second bandwidth state acquiring unit and the total bandwidth state, and the bandwidth control apparatus further includes a bandwidth information communicating unit that notifies each of the transmission bandwidths allocated by the bandwidth state allocating unit to the other bandwidth control apparatuses according to the identification information.

3. The bandwidth control apparatus according to claim 1 , wherein the other bandwidth control apparatuses include a first adjacent bandwidth control apparatus connected to an upstream side of the bandwidth control apparatus and a second adjacent bandwidth control apparatus connected to a downstream side of the bandwidth control apparatus, the second bandwidth state acquiring unit includes: an upstream side bandwidth state acquiring unit that acquires a bandwidth state on the upstream side notified from the first adjacent bandwidth control apparatus through the down stream multiplexed signal line; and a downstream side bandwidth state acquiring unit that acquires a bandwidth state on the downstream side notified from the second adjacent bandwidth control apparatus through the upstream multiplexed signal line, and the bandwidth control apparatus further includes a bandwidth state providing unit that notifies, through the downstream multiplexed signal line, the second adjacent bandwidth control apparatus of a total bandwidth state of the bandwidth state in the bandwidth control apparatus acquired by the first bandwidth state acquiring unit and the bandwidth state on the upstream side acquired by the upstream side bandwidth state acquiring unit, and notifies, through the upstream multiplexed signal line, the first adjacent bandwidth control apparatus of another total bandwidth state of the bandwidth state in the bandwidth control apparatus acquired by the first bandwidth state acquiring unit and the bandwidth state on the downstream side acquired by the downstream side bandwidth state acquiring unit.

4. The bandwidth control apparatus according to claim 3 , wherein the bandwidth states acquired by the first bandwidth state acquiring unit and the second bandwidth state acquiring unit are numbers of access lines in an active state, and the bandwidth state allocating unit calculates, a first total number of access lines in the active state in the bandwidth control apparatus, and a second total number of access lines in the active state in the bandwidth control apparatus and the other bandwidth control apparatuses, and allocates a transmission bandwidth to be controlled in the bandwidth control apparatus based on a ratio of the first total number and the second total number.

5. The bandwidth control apparatus according to claim 2 , wherein the bandwidth states acquired by the first bandwidth state acquiring unit and the second bandwidth state acquiring unit are numbers of access lines in an active state, and the bandwidth state allocating unit calculates, a first total number of access lines in the active state in the bandwidth control apparatus, a second total number of access lines in the active state in the other bandwidth control apparatuses and a third total number of access lines in the active state in the bandwidth control apparatus and the other bandwidth control apparatuses, and allocates a transmission bandwidth to be controlled in the bandwidth control apparatus, based on a ratio of the first total number and the third total number and each of transmission bandwidths to be controlled in the other bandwidth control apparatuses based on a ratio of the second total number and the third total number.

6. The bandwidth control apparatus according to claim 3 , wherein the bandwidth states acquired by the first bandwidth state acquiring unit and the second bandwidth state acquiring unit are numerical values weighted according to effective rates of access lines in an active state, and the bandwidth state allocating unit calculates a first total numerical value weighted according to effective rates of access lines in the active state in the bandwidth control apparatus and a second total numerical value weighted according to effective rates of access lines in the active state in the bandwidth control apparatus and the other bandwidth control apparatuses, and allocates a transmission bandwidth to be controlled in the bandwidth control apparatus based on a ratio of the first total numerical value and the second total numerical value.

7. The bandwidth control apparatus according to claim 2 , wherein the bandwidth states acquired by the first bandwidth state acquiring unit and the second bandwidth state acquiring unit are numerical values weighted according to effective rates of access lines in an active state, and the bandwidth state allocating unit calculates, a first total numerical value weighted according to effective rates of access lines in the active state in the bandwidth control apparatus, a second total numerical value weighted according to effective rates of access lines in the active state in the other bandwidth control apparatuses, and a third total numerical value weighted according to effective rates of access lines in the active state in the bandwidth control apparatus and the other bandwidth control apparatuses, and allocates a transmission bandwidth to be controlled in the bandwidth control apparatus based on a ratio of the first total numerical value and the third total numerical value, and the transmission bandwidths to be controlled in the other bandwidth control apparatuses based on a ratio of the second total numerical value and the third total numerical value.

8. A bandwidth control system including a plurality of bandwidth control apparatuses, each of the bandwidth control apparatuses is connected with other bandwidth control apparatuses in cascade through an upstream multiplexed signal line and a downstream multiplexed signal line, accommodates a plurality of access lines to which user terminals are connected, acquires a total bandwidth state of the plurality of access lines and controls transmission bandwidths of the access lines, the bandwidth control system comprising: a first bandwidth control apparatus that is located at the most upstream side of the cascade connection, notifies a bandwidth control apparatuses connected to a downstream side of a first total bandwidth state of the first bandwidth control apparatus through the downstream multiplexed signal line, calculates a total system bandwidth state by adding the first total bandwidth state to the bandwidth states of other bandwidth control apparatuses acquired through the upstream multiplexed signal line and allocates a transmission bandwidth to be controlled in the first bandwidth control apparatus based on a ratio of the first total bandwidth state and the total system bandwidth state; a second bandwidth control apparatus that is located at the most downstream side of the cascade connection, notifies a bandwidth control apparatus connected to an upstream side of a second total bandwidth state of the second bandwidth control apparatus through the upstream multiplexed signal line, calculates a total system bandwidth state by adding the second total bandwidth state to the bandwidth states of other bandwidth control apparatuses acquired through the downstream multiplexed signal line and allocates a transmission bandwidth to be controlled in the second bandwidth control apparatus based on a ratio of the second total bandwidth state and the total system bandwidth state, and a third bandwidth control apparatus that is located between the first bandwidth control apparatus and the second bandwidth control apparatus of the cascade connection, notifies the bandwidth control apparatus connected to the upstream side of a downstream total bandwidth state, in which a third total bandwidth state of the third bandwidth control apparatus and a fourth total bandwidth state of the bandwidth states of other bandwidth control apparatuses located at the downstream side notified through the upstream multiplexed signal line are added, through the upstream multiplexed signal line, notifies the bandwidth control apparatus connected to the downstream side of an upstream total bandwidth state, in which the third total bandwidth state of the third bandwidth control apparatus and a fifth total bandwidth state of the bandwidth states of other bandwidth control apparatuses located at the upstream side notified through the downstream multiplexed signal line are added, through the downstream multiplexed signal line, calculates a total system bandwidth state by summing the third total bandwidth state, the fourth total bandwidth state and the fifth total bandwidth state, and allocates a transmission bandwidth to be controlled in the third bandwidth control apparatus based on a ratio of the third total bandwidth state and the total system bandwidth state.

9. A bandwidth control method for a bandwidth control apparatus that is connected with a plurality of other bandwidth control apparatuses in cascade through an upstream multiplexed signal line and a down stream multiplexed signal line, accommodates a plurality of access lines to which user terminals are connected, and controls a transmission bandwidth of the access lines, the bandwidth control method comprising: a first bandwidth state acquiring step for acquiring a bandwidth state of the access lines accommodated in the bandwidth control apparatus; a second bandwidth state acquiring step for acquiring bandwidth states in the other bandwidth control apparatuses that are connected to one another in cascade; a bandwidth allocating step for calculating a total bandwidth state of the bandwidth state acquired in the first bandwidth state acquiring step and the bandwidth acquired in the second bandwidth state acquiring step, and allocating a transmission bandwidth to be controlled in the bandwidth control apparatus based on a ratio of the bandwidth state acquired in the first bandwidth state acquiring step and the total bandwidth state; and a bandwidth control step performed by a bandwidth state control unit for controlling, on the basis of the transmission bandwidth allocated in the bandwidth allocating step, transmission bandwidths of the access lines accommodated in the bandwidth control apparatus, wherein upstream signals from the access lines accommodated in the bandwidth control apparatus and upstream signals from the other bandwidth control apparatuses located in a downstream direction are multiplexed for outputting an upstream multiplexed signal through the upstream multiplexed signal line, and a downstream multiplexed signal through the downstream multiplexed signal line is branched for broadcasting to the access lines accommodated in the bandwidth control apparatus as downstream signals and providing to the other bandwidth control apparatuses located in the downstream direction as the downstream signals.

10. The bandwidth control method according to claim 9 , wherein the other bandwidth control apparatuses include a first adjacent bandwidth control apparatus connected to an upstream side of the bandwidth control apparatus and a second adjacent bandwidth control apparatus connected to a downstream side of the bandwidth control apparatus, wherein the second bandwidth state acquiring step comprises: an upstream bandwidth state acquiring step for acquiring a bandwidth state on the upstream side notified from the first adjacent bandwidth control apparatus through the down stream multiplexed signal line; and a downstream bandwidth state acquiring step for acquiring a bandwidth state on the downstream side notified from the second adjacent bandwidth apparatus through the upstream multiplexed signal line; and wherein the method further comprising: a bandwidth state providing step for notifying, through the downstream multiplexed signal line, the second adjacent bandwidth control apparatus of a total bandwidth state of the bandwidth states acquired in the first bandwidth state acquiring step and the bandwidth states acquired in the upstream bandwidth state acquiring step and notifying, through the upstream multiplexed signal line, the first adjacent bandwidth control apparatus of another total bandwidth state of the bandwidth states acquired in the first bandwidth state acquiring step and the bandwidth state acquired in the downstream bandwidth state acquiring step.

11. A bandwidth allocating apparatus that allocates bandwidths of a plurality of bandwidth control apparatuses, each of the bandwidth control apparatuses is connected with other bandwidth control apparatuses in cascade through an upstream multiplexed signal line and a downstream multiplexed signal line, accommodates a plurality of access lines to which user terminals are connected, and controls transmission bandwidths of the access lines, the bandwidth allocating apparatus comprising: a bandwidth state acquiring unit that acquires bandwidth states from each of the plurality of bandwidth control apparatuses together with identification information for identifying the bandwidth control apparatuses; a bandwidth allocating unit that calculates, a total bandwidth state of the bandwidth states acquired by the bandwidth state acquiring unit, and allocates each of transmission bandwidths to be controlled in the respective bandwidth control apparatuses based on a ratio of each of the bandwidth states of the respective bandwidth control apparatuses and the total bandwidth state; and an allocated bandwidth providing unit that provides each of the bandwidth control apparatuses with the bandwidths allocated by the bandwidth allocating unit according to the identification information, and wherein upstream signals from the access lines accommodated in a bandwidth control apparatus and upstream signals from the other bandwidth control apparatuses located in a downstream direction are multiplexed for outputting an upstream multiplexed signal through the upstream multiplexed signal line, and a downstream multiplexed signal through the downstream multiplexed signal line is branched for broadcasting to the access lines accommodated in the bandwidth control apparatus as downstream signals and providing to the other bandwidth control apparatuses located in the downstream direction as the downstream signals.

12. A bandwidth control method for a bandwidth control system including a plurality of bandwidth control apparatuses, each of the bandwidth control apparatuses is connected with other bandwidth control apparatuses in cascade through an upstream multiplexed signal line and a downstream multiplexed signal line, accommodates a plurality of access lines to which user terminals are connected, acquires a total bandwidth state of the plurality of access lines and controls transmission bandwidths of the access lines, the bandwidth control method comprising: steps performed by a first bandwidth control apparatus that is located at the most upstream side of the cascade connection includes: a first total bandwidth state notifying step for notifying a bandwidth control apparatus connected to a downstream side of a first total bandwidth state of the first bandwidth control apparatus through the downstream multiplexed signal line; a total system bandwidth state calculating step for calculating a total system bandwidth state by adding the first total bandwidth state to the bandwidth states of other bandwidth control apparatuses acquired through the upstream multiplexed signal line; and a transmission bandwidth allocating step for allocating a transmission bandwidth to be controlled in the first bandwidth control apparatus based on a ratio of the first total bandwidth state and the total system bandwidth state, steps performed by a second bandwidth control apparatus that is located at the most downstream side of the cascade connection includes: a second total bandwidth state notifying step for notifying a bandwidth control apparatus connected to an upstream side of a second total bandwidth state of the second bandwidth control apparatus through the upstream multiplexed signal line; a total system bandwidth state calculating step for calculating a total system bandwidth state by adding the second total bandwidth state to the bandwidth states of other bandwidth control apparatuses acquired through the downstream multiplexed signal line; and a transmission bandwidth allocating step for allocating a transmission bandwidth to be controlled in the second bandwidth control apparatus based on a ratio of the second total bandwidth state and the total system bandwidth state, steps performed by a third bandwidth control apparatus that is located between the first bandwidth control apparatus and the second bandwidth control apparatus of the cascade connection includes: a downstream total bandwidth state notifying step for notifying the bandwidth control apparatus connected to the upstream side of a downstream total bandwidth state, in which a third total bandwidth state of the third bandwidth control apparatus and a fourth total bandwidth state of the bandwidth states of other bandwidth control apparatuses located at the downstream side notified through the upstream multiplexed signal line are added, through the upstream multiplexed signal line; an upstream total bandwidth state notifying step for notifying the bandwidth control apparatus connected to the downstream side of an upstream total bandwidth state, in which the third total bandwidth state of the third bandwidth control apparatus and a fifth total bandwidth state of the bandwidth states of other bandwidth control apparatuses located at the upstream side notified through the downstream multiplexed signal line are added, through the downstream multiplexed signal line; a total system bandwidth state calculating step for calculating a total system bandwidth state by summing the third total bandwidth state, the fourth total bandwidth state and the fifth total bandwidth state; and a transmission bandwidth allocating step for allocating a transmission bandwidth to be controlled in the third bandwidth control apparatus based on a ratio of the third total bandwidth state and the total system bandwidth state.